losopher's lip, as the door closed.

A letter from Herr Leibnitz set him wondering uneasily what had taken
the young German Crichton from Frankfort, and what he was about in
Paris. They had had many a discussion in this little lodging, but he
was not yet sure of the young man's single-mindedness. The contents of
the letter were, however, unexpectedly pleasing. For it concerned not
the philosopher but the working-man. Even his intimates could not
quite sympathize with his obstinate insistence on earning his living
by handicraft--a manual activity by which the excommunicated Jew was
brother to the great Rabbis of the Talmud; they could not understand
the satisfaction of the craftsman, nor realize that to turn out his
little lenses as perfectly as possible was as essential a part of his
life as that philosophical activity which alone interested them. That
his prowess as an optician should be invoked by Herr Leibnitz gave him
a gratification which his fame as a philosopher could never evoke. The
only alloy was that he could not understand what Leibnitz wanted.
"That rays from points outside the optic axis may be united exactly in
the same way as those in the optic axis, so that the apertures of
glasses may be made of any size desired without impairing distinctness
of vision!" He wrinkled his brow and fell to making geometrical
diagrams on the envelope, but neither his theoretical mathematics nor
his practical craftsmanship could grapple with so obscure a request,
and he forgot to eat while he pondered. He consulted his own treatise
on the Rainbow, but to no avail. At length in despair he took up the
last letter, to find a greater surprise awaiting him. A communication
from Professor Fabritius, it bore an offer from the Elector Palatine
of a chair at the University of Heidelberg. The fullest freedom in
philosophy was to be conceded him: the only condition that he should
not disturb the established religion.

His surprise passed rapidly into mistrust. Was this an attempt on the
part of Christianity to bribe him? Was the Church repeating the
tactics of the Synagogue? It was not so many years since the
messengers of the congregation had offered him a pension of a thousand
florins not to disturb _its_ "established religion." Fullest freedom
in philosophy, forsooth! How was that to be reconciled with impeccable
deference to the ruling religion? A courtier like Descartes might
start from the standpoint of absolute doubt and end i